MCIMX286CVM4B Freescale Semiconductor, MCIMX286CVM4B Datasheet - Page 910

• Manufacturer Part Number: MCIMX286CVM4B
• Description: IC MPU I.MX286 289MAPBGA
• Manufacturer: Freescale Semiconductor
• Series: i.MX28r

Specifications of MCIMX286CVM4B

• Core Processor: ARM9
• Core Size: 32-Bit
• Speed: 454MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, MMC, SmartCard, SPI, SSI, UART/USART, USB OTG
• Peripherals: DMA, I²S, LCD, POR, PWM, WDT
• Program Memory Size: 128KB (32K x 32)
• Program Memory Type: Mask ROM
• Ram Size: 32K x 32
• Voltage - Supply (vcc/vdd): 1.25 V ~ 5.25 V
• Data Converters: A/D 17x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 289-LFBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of I /o: -
• Eeprom Size: -
• Lead Free Status / Rohs Status: Compliant

Thermal-Overload Protection Circuit
is directly used as the precision time base for measuring the frequency of a ring oscillator.
The ring oscillator is normally disabled. There is a 8-bit/16-bit counter connected to the
ring oscillator that performs the frequency measurement. See HW_POWER_SPEED register.
Thus, the counter holds the number of cycles the ring oscillator was able to generate during
one crystal clock period. The natural frequency of the ring oscillator strongly tracks the
silicon process parametrics, that is, faster silicon processes yield ring oscillators that run
faster and thereby yield larger count values. The natural frequency tracks junction temperature
effects on silicon speed as well.
The information given by the speed sensors can be used with the silicon temperature and
process parameters, which can also be monitored by system software. Freescale can provide
a power management application note and firmware that takes full advantage of the on-chip
monitoring functions to enable minimum-voltage operation.
11.9 Thermal-Overload Protection Circuit
The i.MX28 integrates a thermal-overload protection circuit to shut down the device when
the on-die temperature exceeds a programmed target value. It consists of a bipolar based
voltage generator whose characteristics track the on-die temperature. This
temperature-dependent voltage is compared to a fixed voltage level that does not vary with
the temperature to trigger a shut down of the device. The thermal-overload protection circuit
is disabled by default, but can be enabled after the system is up. Its default thermal trip-point
is set to 115degC and can be programmed up to 150degC in 5degC steps. See
HW_POWER_THERMAL register.
11.10 Bandgap Reference Generator
The i.MX28 integrates a bandgap generator which creates supply and temperature stable
voltage and current references for the on-chip blocks. Several bits are provided to adjust
the reference voltages and currents. See HW_POWER_REFCTRL register.
11.11 Interrupts
The power system supports nine CPU interrupt events that are programmable within the
HW_POWER_CTRL register. The interrupts are listed in
Table
11-2.
Table 11-2. Power System Interrupts
HW_POWER_CTRL INTERRUPT BIT
Description
VDDA_BO_IRQ
VDDA Brownout
i.MX28 Applications Processor Reference Manual, Rev. 1, 2010
910
Freescale Semiconductor, Inc.